and neighbours are being forced to take similar action. we're working closely with the devolved administrations to protect people in every part of the uk and, of course, there is now real, real hope that we will soon be rid of this virus, and that prospect is growing with every day that passes and every vaccine dose that is administered. as you know, the uk was the first country in the western world to start using a clinically approved vaccine, and so, please, if the nhs contacts you, then get your vaccine and join the 350,000 people across the uk who have already had theirfirst dose. yes, christmas this year will be different, very different, but we must be realistic.

we're sacrificing the chance to see our loved ones this christmas so we have a better chance of protecting their lives so that we can see them at future christmases. and as sure as night follows day, we'll beat back this virus, we'll defeat it and reclaim our lives. i'm going to hand over now to patrick who is going to go through some of the slides explaining this decision. thank you very much. may i have the first slide, please? this slide is the office for national statistics slide showing infections have risen again in recent weeks. it shows the percentage of positive tests against time, and you can see from july to september it was fairly flat. an increase occurred during september up to a peak, after which the lockdown led to a decrease in the numbers during november, and it is now on the increase again. the lockdown brought

the numbers down and now we are seeing them rising again. next slide, please. this shows the levels on the 29th of november up to the 13th of december. 0n the left hand side is the average cases in the last two weeks to november 29 and on the right—hand side is in mid—december. the darker the colour, the higher the number of cases. what you can see festival is in some areas have got very dark and here it is south wales and the south—east of england, and that the overall cases have increased by more than 50%. a substantial increase in over the period december. if ijust concentrate now on the south—east, east and london, we will see a picture which i think begins to link into

the new virus variant. next slide, please. so this is hospital admissions per day in london, east of england and the south—east from nhs data from september through to now. you can see a gradual increase in the number of hospital admissions per day, and you can see very sharp during december. this virus has taken off, it is moving fast, and it is leading inevitably to a sharp increase in hospital admissions. next slide, please. if we now look just at the areas that are moving into tier 4, as the prime minister has just said, which is areas in london, the south—east and the east, and look at the number of cases, the case rate against time, but you can see is that the number of cases increase or in the case

rate increases dramatically. if you look at the dotted line that is what england as a whole. case rate is increasing took november, decreasing during lockdown and increasing again. but if you look at the solid blue line, which is london and the south—east and the east, in tier 4, you can see a rapid increase, a very sharp increase in rates over the period of december. so we have a particularly fast moving problem with increased numbers in the area going into tier 4, but a generalised increase across the country. next slide, please. i'd like to just to spend a moment talking about the new variant. so the new variant, and viruses mutate all the time, but the new variant contains 23 different changes. many of them are associated with changes in the protein that the virus makes. this is an unusually

large number of variants. it also has variance in areas of the virus that i'm known to be associated with how the virus binds to cells and enters cells. so there are some changes which caused concern in terms of how the virus looks. but on top of that, there are three questions that need to be asked. does the new variant to transmit more readily? ie does it make an increased chance of spreading growth? the second is does it all of the disease, does it make people more sick? and the third is, does it alter the way that the immune system, the way the body responds to it if it has been previously infected, or following the vaccine? i want to deal with the first question. there are three different sources of evidence from genetic studies to frequency studies to laboratory studies, all of which come together to suggest this virus has a significant substantial

increase in transmissibility. this is also highlighted in this graph, which shows the proportion of all the cases that were due to the new variant. so the new variant was first thought to have occurred sometime in mid september in london or kent, and by the middle of november, about 28% or so of the cases in london and the south—east, and slightly lower in the east of england, where due to the new variant. so it had grown rapidly. by the week commencing the 9th of december these figures were much higher. so in london, over 60% of all the cases where the new variant. so what this tells us is that this new variant not only moves fast, it is increased in its terms of being able to transmit

but it is a beating all of the others in terms of transmission and has become dominant. this virus transmits and breads fast. does it alter the disease course? the answer seems to be know as far as we can tell at the moment. there is no evidence it causes a more severe disease, more hospitalisation, more trouble than the other virus. it basically looks similar. does it alter the immune response, or is the immune system less able to recognise it? there are theoretical reasons to suspect some of the changes might alter some of the immune response but nothing has been seen to suggest that is the case, and our working assumption at the moment from all of the scientists is that the vaccine response should be adequate for this virus. that obviously needs to be looked at going forward and we need to keep vigilant about this, but the big change therefore is not disease progress, not the immunity, but transmission. this virus spreads more easily and therefore are measures are needed to keep it under control. we absolutely need to stick

to the basics of making sure that we reduce our contact, reduce ability for the virus to spread, and that is the recent topic measures are required to keep this variant of the control. thanks very much, patrick. chris, is there anything you want to add? thank you both very much. let's go to questions from the public and then the media. first to laura from worthing. why are shielded people still expected to work in tier 3? as someone who has lost loved ones, this terrifies me. well, laura, your question of why shielders are still expected to work in tier 3, those who are shielding, those who are vulnerable, should of course take every step to protect themselves and, laura, i hope very much that you are not being asked to work if you are shielding. chris?

i am sorry to hear about your two relatives who died from this virus. it is a very dangerous virus for many people. but shielding patterns are actually being looked at again. the view about shielding is that in the first wave, shielding did many things that were useful but also many things that were actively harmful and we therefore changed the model of shielding since the first wave, and that includes people being able to get out more in many situations and also areas around work. this is something people are keeping looking at to get the optimal balance between isolating people too much and isolating them enough from the virus yellow thanks very much. let's go to mike from cheshire. he asks... in the daily updates, people testing positive, could you also provide the number of people who have the vaccine? mike, thanks for that. and yes, as you have

heard from me just now, the figure that i have been given today is 350,000 have so far had theirfirst dose. we will make sure we keep people regularly updated on the roll—out of the vaccine. let's go to laura kuenssberg of the bbc. thank you very much. there were calls for you to drop the plans for christmas last week, just a few days ago, but on wednesday you told me and our viewers it would be inhuman to change the plans. now that is exactly what you have done. aren't there are millions of people whose plans have just been torn up who are entitled to feel that you have left this too late and caused them more personal disruption and upset by doing so? can i ask the medics, you have shed the analysis of this new variant and you mentioned porton down have been looking

at this in an earlier press conference this week. can you say if porton down have completed their assessments of it? professor chris whitty, if someone is packing a bag right now, trying to leave the south—east by midnight tonight, what should they do? laurette, let me first of all say to everybody who has made plans for christmas, as i said earlier on, everyone who has thought about it, all the care and love that has gone into plans for christmas, we of course bitterly regret the changes that are necessary but, alas, when the facts change you have to change your approach and the briefing i had yesterday about this mutation of the virus, particularly about the speed of transmission, was not possible to ignore. when the virus changes its method of attack, we as a country have to change our method of defence, and that is what we are doing.

there are stills a number of flood warnings in force across england, wales and scotland. find out if your area is affected on the bbc weather website, and there is some more rain on the way. in the form of showers to the rest of the week and you can see on the satellite picture we have had plentiful shower clouds pushing in from the west, the showers will continue through tonight, some heavy so continue through tonight, some heavy so possibly with some hail and thunder, the further east you are not as many showers, more in the way of clear skies but it stays pretty blustery out there so temperatures won't drop too far. four to 8 degrees. the values we can expect as we start sunday morning. another sunshine and showers day tomorrow come and share with them portable in the west. not as many showers in the east. both the afternoon knows the showers becoming fewer and further between, we will see briefly a spell of dryer brighter weather. some heavy downpours return to parts of

northern ireland and the front northwest was the gusts of 50 mph or more. temperatures touchdown on the date, nine, ten or” more. temperatures touchdown on the date, nine, ten or 11 degrees. more. temperatures touchdown on the date, nine, ten or” degrees. rain and hills note moves the northern half of the uk and out of south cloud and rain will be gathering. as a frontal system approaches. the system will move across the southern half of the uk particularly as we had to sunday night and into monday with some epics of rain to the south, of our fragile system some very mild air, to the north some rather cold air. so a big split in temperature fortunes on monday. heavy moving its way eastwards away from parts of england as we go through the morning, behind it a lot of cloud left behind, northern ireland sinks of sunshine, rain and hilssner moving in from parts of scotland. temperatures of real rain in aberdeen, i3 scotland. temperatures of real rain in aberdeen, 13 the hyatt in london. then as a move towards the middle of the week another area of low pressure is going you bring another dose of rain across the south. at

high pressure will build its way into her as the second half of the week. that means drier weather at the time for christmas. but also colder weather. as we had through the week temperatures are set to drop down into single digits by christmas eve and christmas day but should be largely dry.

this is bbc news the headlines at 8pm. nearly 18 million people in london and south—east england move into stricter tier 4 restrictions from midnight — people must stay at home, and non—essential shops have to close. for those in tier 4 — it means the relaxation of rules at christmas has been scrapped — and reduced to one day, the 25th, for the rest of england. we must be realistic. we are sacrificing the chance to see our loved ones this christmas so we have a better chance of protecting their lives so that we can see them in the future christmases. the new restrictions are due to a spike in cases — that's being blamed

on a fast—spreading